Kobe Bryant was purple and gold as a 13-year-old -- signing his middle school friend's yearbook with "How bout those Lakers" -- and now the book can be yours.
Iconic Auctions has the super-unique piece of memorabilia on the auction block ... and it's pretty amazing.
In 1992, Kobe -- who just returned to the U.S. from Italy -- attended Bala Cynwyd Middle School in Pennsylvania ... where he played on the basketball team.
Bryant arrived midway through the school year, so he didn't have a standard school photo.